¹H NMR spectroscopic method for diagnosis of malabsorption syndrome: a pilot study

Abstract

Despite its well-documented limitations, colorimetry has been commonly used for the d-xylose test in the diagnosis of malabsorption syndrome (MAS). With a possibility of overcoming its limitations, the use of (1)H NMR spectroscopy for D-xylose test is explored herein. Urine samples from 35 adults with suspected MAS were obtained before and after oral ingestion of D-xylose. The diagnosis of MAS was based on fecal fat (72 h excretion using Van de Kamer's technique, normal < 7 g/24 h and/or Sudan III stain of spot stool specimen, normal<or=10 droplets/high power field) and/or endoscopic duodenal biopsy. Urinary excretion of D-xylose over 5 h after consumption of 5 g D-xylose, using both colorimetry and NMR was compared (normal>or=1 g/5 g/5 h). In vitro experiments on the standard specimens of D-xylose were also performed independently using both methods. Colorimetry showed a lower value for the quantity of D-xylose excreted in urine than NMR [median 0.73 (0.17-1.89 g) vs 1.37 (0.17-3.23 g), respectively; p<0.0001, Wilcoxon's signed ranks test]. Colorimetry and NMR correctly diagnosed 11/12 and 10/12 (p=N.S.) patients with MAS and 14/23 and 20/23 (p<0.05) without MAS, respectively. Sensitivity and specificity of colorimetry and NMR were 91.6 and 60.7% vs 83.3 and 86.9%, respectively. In in vitro experiments, the values obtained for standard xylose using NMR showed a maximum error of 7%, whereas the colorimetric method showed 20%. The NMR method is simple and may be more accurate for the D-xylose absorption test. Colorimetry was found to be inferior as compared with NMR due to its low specificity.

Malabsorption syndrome with and without small intestinal bacterial overgrowth: A study on upper‐gut aspirate using 1H NMR spectroscopy

“…It is becoming an important technique in the area of metabonomics (16,17). In the present study we explored the application of 1 H NMR spectroscopy for studying the upper-gut aspirates of patients with MAS and controls with the following aims: 1) to qualitatively and quantitatively evaluate the presence of various biochemical constituents in the upper-gut aspirate, 2) to investigate the relationship of these biochemical constituents with the degree of bacterial overgrowth in the upper gut, and 3) to assess pathophysiological significance of these chemicals.…”

1H NMR spectroscopy of ascitic fluid: discrimination between malignant and benign ascites and comparison of the results with conventional methods

“…2. The procedure followed for quantification of the metabolites is the same as reported previously (18). Deuterium oxide (D 2 O; 99.98 atom% D) and the sodium salt of 3-trimethylsilyl-(2,2,3,3-d 4 )-propionic acid were purchased from SigmaAldrich (Milwaukee, WI, USA).…”

“…High-resolution 1 H NMR spectroscopy of body fluids coupled with statistical analysis has emerged as an important tool for differential diagnosis of diseases, and it can also provide insights into their pathogenesis (18)(19)(20). This prompted us to explore the use of quantitative 1 H NMR spectroscopy of ascitic fluid specimens with the specific aims to: (a) study the metabolic profile of ascitic fluid; (b) study the differences between various metabolic indices in malignant and benign ascitic fluids; (c) apply multivariate discriminant function analysis (DFA) to find potentially interesting metabolites involved in the differentiation process and to generate a model for discrimination; (d) investigate if, in cytologically negative but doubtful malignant cases, 1 H NMR can provide more information.…”

Correlation of Age-Related Metabonomic Changes in 1H NMR Serum and Urine Profiles of Rats with Cognitive Function

“…For CPMG experiment total echo time of 0.64 ms with 150 echoes was used. Semi quantitative concentrations of metabolites were obtained using the integral area of respective metabolite marker signal with reference to the integral area of TSP in CPMG spectra [18].…”